Giant magnetoelectric effect in magnetic tunnel junctions coupled to an electromagnetic environment

TL;DR

This paper investigates how an electromagnetic environment influences magnetization dynamics and voltage responses in ultra-small magnetic tunnel junctions, revealing a strong, non-linear effect that enables detection of magnetization precession.

Contribution

It demonstrates that the electromagnetic environment significantly alters voltage behavior in magnetic tunnel junctions, introducing non-linearity and enabling new detection methods.

Findings

Voltages can reach the order of the driving frequency even at small precession angles.

The environment causes a highly non-linear voltage response as a function of the precession cone angle.

Potential applications include detecting local magnetization precessions and probing the electromagnetic environment.

Abstract

We study the magnetization dynamics in ferromagnet$\mid$insulator$\mid$ferromagnet and ferromagnet$\mid$insulator$\mid$normal metal ultra-small tunnel junctions, and the associated voltage drop in the presence of an electromagnetic environment assisting the tunneling processes. We show that the environment strongly affects the resulting voltage, which becomes a highly non-linear function of the precession cone angle $\theta$. We find that voltages comparable to the driving frequency $\omega$ can be reached even for small precession cone angles $\theta$, in stark contrast to the case where the environment is absent. Such an effect could be useful for the detection local magnetization precessions in textured ferromagnets or, conversely, for probing the environment via the magnetization dynamics.